The brain remains one of the most mysterious systems in the universe ? one critical challenge in gaining understanding has been that its constituent elements have features that span across many length scales, in three-dimensions, from the microscopic to the microscopic. In the last few years, new developments in tissue clearing methods and microscopy promise to allow the exploration of the brain over its natural range of scales. We propose to acquire a high performance multi-wavelength lightsheet microscope for a multi-user cellular imaging core that is capable of imaging centimeter size brain and tissue sections while maintaining sub-cellular resolution. This versatile instrument can be used with all currently developed tissue clearing agents, as well as with live tissue, and will be applied to myriad systems that span critical Neuroscience questions, from the role of molecules and genes in development, to the role of experience and learning, in shaping neural circuits.